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| author | Denys Vlasenko | 2020-02-22 19:38:40 +0100 |
|---|---|---|
| committer | Denys Vlasenko | 2020-02-24 19:20:51 +0100 |
| commit | 1555895b4af44ce47fe2365aec82e8e67c685f08 (patch) | |
| tree | bd821be779bc1d489ac966b0d83e4a5e026979dd /shell/ash.c | |
| parent | 823318822ccb0e0910abbd4e1f983637dfd9d3c0 (diff) | |
| download | busybox-1555895b4af44ce47fe2365aec82e8e67c685f08.zip busybox-1555895b4af44ce47fe2365aec82e8e67c685f08.tar.gz | |
ash: expand: Fix multiple issues with EXP_DISCARD in evalvar
Upstream commit:
Date: Wed, 12 Sep 2018 14:27:16 +0800
expand: Fix multiple issues with EXP_DISCARD in evalvar
The commit 3cd538634f71538370f5af239f342aec48b7470b broke parameter
expansion in multiple ways because the EXP_DISCARD flag wasn't set
or tested for various cases:
$ src/dash -c 'var=; echo ${var:+nonempty}'
nonempty
$ src/dash -u -c 'unset foo bar; echo ${foo+${bar}}'
dash: 1: bar: parameter not set
$ src/dash -c 'foo=bar; echo ${foo=BUG}; echo $foo'
barBUG
bar
$
This patch fixes them by introducing a new discard variable that
tracks whether the extra word should be discarded or not when it
is parsed.
Reported-by: Martijn Dekker <martijn@inlv.org>
Fixes: 3cd538634f71 ("expand: Do not reprocess data when...")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reported-by: Martijn Dekker <martijn@inlv.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'shell/ash.c')
| -rw-r--r-- | shell/ash.c | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/shell/ash.c b/shell/ash.c index 425da6b..d0d99f6 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -7454,6 +7454,7 @@ evalvar(char *p, int flag) int patloc; int startloc; ssize_t varlen; + int discard; int quoted; varflags = (unsigned char) *p++; @@ -7469,33 +7470,31 @@ evalvar(char *p, int flag) if (varflags & VSNUL) varlen--; + discard = varlen < 0 ? EXP_DISCARD : 0; + switch (subtype) { case VSPLUS: - varlen = -1 - varlen; + discard ^= EXP_DISCARD; /* fall through */ case 0: case VSMINUS: - p = argstr(p, flag | EXP_TILDE | EXP_WORD); - if (varlen < 0) - return p; + p = argstr(p, flag | EXP_TILDE | EXP_WORD | (discard ^ EXP_DISCARD)); goto record; case VSASSIGN: case VSQUESTION: - if (varlen >= 0) - goto record; - p = subevalvar(p, var, 0, startloc, varflags, - flag & ~QUOTES_ESC); + (flag & ~QUOTES_ESC) | (discard ^ EXP_DISCARD)); - if (flag & EXP_DISCARD) - return p; + if ((flag | ~discard) & EXP_DISCARD) + goto record; varflags &= ~VSNUL; + subtype = VSNORMAL; goto again; } - if (varlen < 0 && uflag) + if ((discard & ~flag) && uflag) varunset(p, var, 0, 0); if (subtype == VSLENGTH) { @@ -7503,7 +7502,7 @@ evalvar(char *p, int flag) if (flag & EXP_DISCARD) return p; cvtnum(varlen > 0 ? varlen : 0, flag); - goto record; + goto really_record; } if (subtype == VSNORMAL) @@ -7528,7 +7527,7 @@ evalvar(char *p, int flag) } #endif - flag |= varlen < 0 ? EXP_DISCARD : 0; + flag |= discard; if (!(flag & EXP_DISCARD)) { /* * Terminate the string and start recording the pattern @@ -7541,9 +7540,10 @@ evalvar(char *p, int flag) p = subevalvar(p, NULL, patloc, startloc, varflags, flag); record: - if (flag & EXP_DISCARD) + if ((flag | discard) & EXP_DISCARD) return p; + really_record: if (quoted) { quoted = *var == '@' && shellparam.nparam; if (!quoted) |